This invention relates to apparatus for computing the period of the transmission from a radar set, especially that of a radar which periodically transmits a burst of pulses.
One of the important missiles developed by a foreign power employs an active homing radar system using a sector-scan antenna. The radar emits a burst of pulses each time the antenna passes the 5.degree. left-of-center position. The period between bursts may vary for different missiles, though generally remaining in the approximate range of 2.0 to 3.5 seconds. For counterintelligence purposes, it is necessary to determine the period of the sector scan, which is equivalent to the interval between the beginning of odd-numbered (or even-numbered) bursts.
Previously, determination of the period was accomplished by displaying the received radar signal on a PPI scope, noting the occurrence of the range mark bursts on the display and using a counter to determine the time interval between every other burst. The present invention automatically determines the sector-scan period.